A sector of a circle has an area of 55 cm2. If the radius of the circle is 10 cm, calculate the angle of the sector
[\pi = 22/7]
A
45o
B
63o
C
75o
D
90o
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Area of a sector = \(\frac{\theta}{360}\times \pi r^2\)
55 = \(\frac{\theta}{360}\times \frac{22}{7}\times \frac{10\times 10}{1}\)
\(\theta = \frac{360 \times 55 \times 7}{22 \times 10 \times 10}\)
\(\theta = 63^{\circ}\)
Source: Myschool Past Questions Archive (Record #8426)